2026-27 Budget CGT & Negative Gearing Calculator

CGT new rules vs current law —
how much will you really pay?

Model your capital gains tax under both the 50% discount regime and the 1 July 2027 reforms (CPI indexation + 30% minimum), and see how the negative gearing changes hit your deduction. Free Melbourne buyers agent tool, sourced from 2026-27 Federal Budget BP2 and ATO methodology.

By Yan Zhu · Co-Founder & Chief Data Officer·Reviewed by Joey Don · Co-Founder & CEO·Updated 2026-05-19

50%

Current discount

30%

New minimum rate

CPI

Indexed cost base

Asset details

Asset type

Purchase datedd/mm/yyyySale datedd/mm/yyyy

Purchase price (AUD)

Sale price (AUD)

Implied pre-tax growth4.28% p.a.CAGR of price only

Acquisition & disposal costs

Purchase costs

Stamp duty, conveyancing, loan fees.Selling costs

Agent commission, marketing, legal.

Your tax position

Annual income before sale$200,000

47% marginal

Salary + other taxable income. Progressive FY 2027-28 brackets (incl. 2% Medicare levy above $18,200).Inflation assumption (CPI)2.5%Affects: new rulesIndexes the cost base so only the real gain above inflation is taxed. Higher CPI → lower new-rule tax.

Proceeds after tax$1,344,752Sale − selling costs − tax

Profit after tax$504,752After-tax gain over cost base

Tax$125,248Rules applicable at sale date

After-tax CAGR3.19% p.a.Annualised on invested capital

Tax difference (new − current)

-$22,802

−$22,802 from indexation reducing taxable by $48,515

Current law

50% CGT discount

Tax payable$148,050

Gross capital gain$630,000

Taxable after 50% discount$315,000

Proceeds after tax$1,321,950

From 1 Jul 2027

CPI indexation + 30% minimum

Tax payable$125,248

Pre-2027 portion (50% discount)$58,899

Post-2027 portion (indexed)$66,349

Proceeds after tax$1,344,752

Detailed calculation breakdown

Gross capital gainNet sale proceeds − cost base.$630,000

Net cost base (incl. costs)Purchase price + acquisition costs.$840,000

Net sale proceeds (less costs)Sale price − selling costs.$1,470,000

Transitional split (assets owned before 1 Jul 2027)

Asset value at 1 Jul 2027ATO geometric apportionment: cost base × (proceeds / cost base)^(pre-reform years / total years).$1,090,635

Pre-2027 gain (50% discount applies)$250,635

Pre-2027 taxable after 50% discount$125,317

Indexed cost base of post-2027 portion$1,328,832

Post-2027 taxable (real) gain$141,168

Minimum-tax top-up (if marginal < 30%)$0

Total taxable under new rules$266,485

Tax comparison

Tax, current law (50% discount)$148,050

Tax, new rules$125,248

Tax-bracket stacking · FY 2027-28

Capital gains are added to your assessable income and taxed progressively. Larger gains can push slices into higher brackets.

Your income: $200,000Taxable gain: $266,485Total for stacking: $466,485

18%

32%

39%

47%

Bracket	Rate	Filled by income	Gain in slice	Tax on gain
0 – $18,200	0%	$18,200	$0	$0
$18,201 – $45,000	18%	$26,800	$0	$0
$45,001 – $135,000	32%	$90,000	$0	$0
$135,001 – $190,000	39%	$55,000	$0	$0
$190,001+	47%	$10,000	$266,485	$125,248
Total			$266,485	$125,248

What's changing — and what isn't

CPI indexation

Cost base uplifted by CPI over the holding period. Only the real gain above inflation is taxed under the new rules.

30% minimum rate

A floor rate of 30% applies to real capital gains accruing from 1 July 2027. No impact on those already taxed at 30%+. Means-tested payment recipients exempt.

Negative gearing limited

Losses on established residential properties bought after 12 May 2026 can only be deducted against future residential property income or CGT. New builds preserved.

What's NOT changing

Main residence exemption · SMSF treatment · pre-12 May 2026 holdings · CGT on assets sold before 1 Jul 2027 · 50% discount on pre-2027 portion of gains.

Common questions

Do the new CGT rules apply to assets I already own?

Only to the portion of gain accruing after 1 July 2027. Gains accrued before that date keep the 50% discount under the transitional split, calculated either by independent valuation or the ATO apportionment formula.

Does the 30% minimum hit high-income earners?

What about my main residence?

How does negative gearing work for new builds?

Is this financial advice?

References & methodology

Every rate, threshold, and formula in this calculator traces back to primary sources. The 30% minimum-rate floor and CPI-indexation formula come from 2026-27 Budget Paper No. 2; the FY 2027-28 progressive brackets follow the legislated rates (including the 2% Medicare levy above $18,200); the geometric apportionment uses the ATO's standard pre/post-reform split formula.

1.2026-27 Federal Budget — Budget Paper No. 2 — Negative gearing changes & CPI-indexed CGT cost base for assets sold on/after 1 Jul 2027.

2.ATO — Capital gains tax (CGT) — Current 50% discount rules, CGT events, cost base inclusions.

3.ATO — Indexation method (for assets acquired before 21 Sep 1999) — Methodology re-introduced in the 2027 reforms for the post-2027 cost-base uplift.

4.ABS — Consumer Price Index (CPI), Australia — Source of the CPI rate used to index the cost base under the new regime.

5.RBA — Cash Rate Target — Reference for the discount rate input on the negative-gearing NPV comparator.

6.Treasury — Tax Expenditures and Insights Statement — Treasury estimates of the value of the 50% CGT discount + negative gearing deductions.

CGT new rules vs current law —how much will you really pay?